As 2020 approaches, preparations in the maritime industry are underway to meet the new International Maritime Organization (IMO) 2020 sulphur cap that will drop from the current 3.50% limit to 0.50%, a significant reduction that will require a range of strategies to achieve.
To specifically address the needs of medium-speed marine engines, ExxonMobil has recently added Mobilgard™ M420 to its long-established Mobilgard™ M Series of advanced marine lubricants.
A 20 base number (BN) oil, Mobilgard M420 has been rigorously tested specifically for use in medium speed engines using fuels that comply with the IMO global 0.50% percent sulphur cap. Thus far, the lubricant has received “no objection letters” from leading engine builders, including MAN ES and Wärtsilä.
Formulated to help protect against deposits on under-crowns, crankcases, ring belts and camshafts, Mobilgard M420 also helps to minimise lubricant consumption and reduce maintenance and operational costs by extending the life of critical wear surfaces and optimising component life.
“Mobilgard M420 builds out our medium speed oil engine lubrication portfolio – were taking it into the regime where we’re making the lubricant match the future fuel sulphur levels,”explains Steve Walker, Global Marine Equipment Builder Manager at ExxonMobil.
“It’s the result of about 4 years of research, looking at what was needed to match the engine requirements with the correct fuel sulphur level,”Walker adds. “And we knew that what we have in the portfolio so far is on the high-end from the base number perspective.”
With the introduction of low sulphur fuels, the use of higher BN lubricants can lead to ash in the exhaust as acid neutralisation additives remain unused, resulting in inefficiencies and increased maintenance requirements. To counter these issues, Mobilgard M420 has been formulated for use on vessels running on 0.50% or 0.10% sulphur fuels.
The low BN formulation means that Mobilgard M420 is also proven for use with engines that run on liquefied natural gas (LNG), which ensures that deep-sea and coastal vessels with dual-fuel engines can continue using a single lubricant irrespective of their fuel selection.
“The field testing has been extensive, both for the medium speed engines and with the major manufacturers,” Walker says. “There’s been 6,000 hours of field trials for MAN and 4,000 for Wärtsilä. We had to make sure this oil actually performs in the field.”
“Not only do we test in the field, but we also have a modelling system,” says Luca Volta, Maritime Fuels Venture Manager at ExxonMobil. “We have a one-piston engine that we use to test the formulation of our fuels and lubricants. As a tangible example, for fuels, the combustion characteristics are really important, and that’s why we’ve invested so much in R&D to make sure the fuel burns properly. It’s all about efficiency – getting the energy you pay for – and avoiding problems such as carbon deposits and increased maintenance costs.”
Steve Walker adds, “The modelling system works as a screening test to help reduce the broadness of formulation options. So, when we put the lubricant into the real-life field trial, we have a greater degree of certainty of how it will work.”
“Fuels and lubricants have to work together to ensure sulphur reduction. ExxonMobil provides services that monitor the performance of the lubricant as well as services on the fuel side and technical support to help shipowners and customers,” says Luca Volta.
Vessel operators are encouraged to implement Mobil Serv℠ Lubricant Analysis, a full spectrum service to analyse used oil. The service for four-stroke engines includes the company’s patented DAC test, which checks lubricant samples for asphaltene contamination. Left undetected, this could lead to piston damage and excessive oil consumption.
“Used in combination with Mobil Serv Lubricant Analysis, Mobilgard M420 can help ensure operators safely and efficiently comply with the IMO sulphur cap, without compromising on vessel performance,” Steve Walker says.
When asked about the future, Walker says he expects manufacturers to invest heavily on developing new engines over the next several years.
“The challenge is that much of the changes will be driven by future legislation. And if you look at the legislation construct that’s being talked about now, the focus is around greenhouse gas,” Walker explains.
“If we want to make the diesel engine more efficient, we have to increase pressures and temperatures, and as a result of that, the lubricants have to step in phase with those conditions,” he adds. “So, as the new engine designs come out, they will be chasing better CO2 emissions, and ExxonMobil will develop lubricants that have better thermal performance to enable them to continue to keep the engines clean and working well. It will be all about chasing better CO2 efficiency.”
Visit ExxonMobil’s “Journey to 2020” information hub for further guidance and insights.